scholarly journals MODELING OF GAS-DYNAMIC PROCESSES IN THE ELEMENTS OF IMPULSE EJECTOR

2021 ◽  
pp. 66-72
Author(s):  
G. O. Voropaiev ◽  
Ia. V. Zagumennyi ◽  
N. V. Rozumnyuk
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Dynamic Processes ◽  
Stable Operation ◽  
Operating Pressure ◽  
Gas Generator ◽  
Gas Dynamic ◽  
Ejector Nozzle

The paper presents the numerical results on gas-dynamic processes in various elements of the impulse ejector, including pre-chamber, supersonic nozzle and mixing chamber, to determine optimal geometric parameters providing the given flow rate characteristics. At an extra-high pressure of the ejecting gas (>100 bar) it is impossible to create a nozzle design with continuously changing cross-sectional area and limited nozzle length. So, it is necessary to place a pre-chamber between the gas generator and the ejector nozzle for throttling full gas pressure. In order to optimize the pre-chamber parameters in the ejector with discrete holes of the gas generator and the operating pressure in the range of 400÷1000 bar, a series of calculations were performed to determine the pre-chamber parameters, ensuring stable operation of the supersonic annular nozzle at the high pressure of 35÷45 bar and the flow rate of 0.5÷0.6 kg/s. 3D numerical simulation of the gas flow into the pre-chamber through the gas generator holes shows the degree of the flow pattern non-uniformity in the pre-chamber at the ejector nozzle inlet is quite low. This justifies the numerical simulation of gas flow in the ejector in axisymmetric formulation and allows restricting the number of the gas generator holes without inducing significant non-uniformity in the azimuthal direction.

Simulation of CO2 removal from pressurized natural gas stream contains high CO2 concentration by absorption process using membrane contactors

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamza A. Ahmed ◽  
Harith N. Mohammed ◽  
Omar S. Lateef ◽  
Ghassan H. Abdullah
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Contact Area ◽  
Gas Flow ◽  
Membrane Properties ◽  
Operating Pressure ◽  
Gas Flow Rate ◽  
Membrane Contactors

AbstractDespite the importance of natural gas (NG) as an energy source, there is a lot of pressurized landfill gas not exploited so far because it contains high CO2 concentration. Therefore, this study aimed to develop a 2-D mathematical model to simulate CO2 removal from NG stream contains high CO2 concentration up to 70% at high-pressure up to 60 bar using three different dimensions of polyvinylidene fluoride (PVDF) hollow fiber membrane contactors. Aqueous solutions of activated methyldiethanolamine (MDEA) with piperazine (PZ) were adopted. The performance of considered absorbent at high-pressure was evaluated at the non-wetting mode condition of membrane contactor. Moreover, the effect of pressure, contact area, gas flow rate, MDEA concentration into the amine mixture, PZ concentration, temperature and membrane properties were theoretically investigated. The findings stated that activated MDEA had different performance in terms of membrane wetting compared with other amines, which used at high pressure in previous studies. In addition, the simulation results showed that CO2 removal efficiency was significantly enhanced, when the operating pressure, contact area, PZ concentration and temperature were increased. However, increasing gas flow rate leads to reduce CO2 removal efficiency. Furthermore, the CO2 absorption was significantly improved by adding a small amount of PZ to MDEA. The predicted model results showed a good agreement with experimental data obtained from the literature.

scholarly journals Investigation on influences of loose gas on gas-solid flows in a circulating fluidized bed (CFB) reactor using full-loop numerical simulation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengju Huo ◽  
Xiaohong Li ◽  
Yang Liu ◽  
Haiying Qi
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Separation Efficiency ◽  
Circulation Rate ◽  
Solid Mass ◽  
Gas Flow Rate ◽  
Gas Leakage ◽  
Mass Circulation

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.

Improvement of the Operating Processes in Boiler Furnaces of TÉTs-21 with the Help of Numerical Simulation of Thermal Gas Dynamic Processes

2003 ◽  
Vol 37 (5) ◽  
pp. 297-301
Author(s):  
A. P. Tishin ◽  
I. T. Goryunov ◽  
Yu. L. Gus'kov ◽  
D. A. Barshak ◽  
G. V. Presnov ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Dynamic Processes ◽  
Gas Dynamic

Experimental, Numerical, and Statistical Investigation of Two Phase Flow in a Cylindrical Perforation Tunnel

2021 ◽  
Author(s):  
Ekhwaiter Abobaker ◽  
Abadelhalim Elsanoose ◽  
Mohammad Azizur Rahman ◽  
Faisal Khan ◽  
Amer Aborig ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Statistical Analysis ◽  
Flow Rate ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Gas Flow Rate ◽  
Two Phase ◽  
Flow Through

Abstract Perforation is the final stage in well completion that helps to connect reservoir formations to wellbores during hydrocarbon production. The drilling perforation technique maximizes the reservoir productivity index by minimizing damage. This can be best accomplished by attaining a better understanding of fluid flows that occur in the near-wellbore region during oil and gas operations. The present work aims to enhance oil recovery by modelling a two-phase flow through the near-wellbore region, thereby expanding industry knowledge about well performance. An experimental procedure was conducted to investigate the behavior of two-phase flow through a cylindrical perforation tunnel. Statistical analysis was coupled with numerical simulation to expand the investigation of fluid flow in the near-wellbore region that cannot be obtained experimentally. The statistical analysis investigated the effect of several parameters, including the liquid and gas flow rate, liquid viscosity, permeability, and porosity, on the injection build-up pressure and the time needed to reach a steady-state flow condition. Design-Expert® Design of Experiments (DoE) software was used to determine the numerical simulation runs using the ANOVA analysis with a Box-Behnken Design (BBD) model and ANSYS-FLUENT was used to analyses the numerical simulation of the porous media tunnel by applying the volume of fluid method (VOF). The experimental data were validated to the numerical results, and the comparison of results was in good agreement. The numerical and statistical analysis demonstrated each investigated parameter’s effect. The permeability, flow rate, and viscosity of the liquid significantly affect the injection pressure build-up profile, and porosity and gas flow rate substantially affect the time required to attain steady-state conditions. In addition, two correlations obtained from the statistical analysis can be used to predict the injection build-up pressure and the required time to reach steady state for different scenarios. This work will contribute to the clarification and understanding of the behavior of multiphase flow in the near-wellbore region.

Numerical Simulation and Experimental Study on Tar Decomposition of Low-Pressure Ejection Type Burner

2015 ◽  
Vol 1092-1093 ◽  
pp. 200-206
Author(s):  
De Fan Qing ◽  
Mao Kui Zhu ◽  
Yang Cheng Luo ◽  
Ya Long Zhang ◽  
Ai Rui Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Low Pressure ◽  
Orthogonal Test ◽  
Nozzle Diameter ◽  
Design Parameters ◽  
Minor Effect ◽  
Gas Flow Rate ◽  
Tar Cracking

The tar decomposition of low-pressure ejection type burner was researched. The burner used software to simulate and analyse impact of the nozzle diameter d, the gas flow rate V and the distance of the nozzle to the wall L on tar cracking. The orthogonal test were used for design parameters d, V and L, the optimization values of these three parameters were carried out, and experimental method was used for test the numerical simulation results. Numerical simulation and experimental results showed that the greatest impact on tar cracking is the nozzle diameter d, the minor effect is the distance of the nozzle to the wall L and the weakest effect is the gas flow rate V, and when the nozzle diameter d=4 mm, the distance L=18 mm and the gas flow rate V=0.10 m3/h, the tar cracking is the most efficiency.

scholarly journals Measurement Standards of Ukraine for Gas Volume Flow Rate at Pressures of 1 MPa to 5 MPa

2021 ◽  
Vol 2 ◽  
Author(s):  
Mykhailo Rozhnov ◽  
Dmytro Melnyk ◽  
Ovsiy Levbarg
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Primary Standard ◽  
Metrological Traceability ◽  
Gas Flow Rate ◽  
Flow Measurements ◽  
Working Standard ◽  
Measurement Standards ◽  
Primary Measurement

The characteristics of the primary measurement standards of the volume gas flow rate at high pressure developed in various countries are considered. A hierarchical scheme for gas flow measuring instruments and a corresponding metrological traceability chain are presented. Described is a PVTt method, on which the primary standards of gas flow rate used in the USA, France, Japan, and Taiwan are based. The need to create in Ukraine primary measurement standards of gas flow rate at high pressure covering different parts of the total flow rate interval from 0,3 m3/h to 1800 m3/h at a pressure of 1 MPa to 5 MPa is substantiated. Metrological traceability of gas flow measurements is realized through a sequence of critical flow Venturi nozzles, which play a role of the reference flow rate material measures. The standards might be used to calibrate the primary reference Venturi nozzles of the most common 0,1 mm to 8 mm diameters. The characteristics and parameters of the standards are determined. By their metrological and technical characteristics, the standards will correspond to the state-of-the-art level. According to the programme of developing the measurement-standard facilities in Ukraine, in 2019 the primary standard PVTt-65 was created and work had started on the development of the primary standard PVTt-1800 and the working standard PE-5400. A detailed study of the metrological characteristics of the measurement standards will be the topic of further work.

PREDICTION OF CONDENSATE FLOW RATES IN LARGE DIAMETER HIGH PRESSURE WET GAS PIPELINES

1978 ◽  
Vol 18 (1) ◽  
pp. 171 ◽  
Author(s):  
R. S. Cunliffe
Keyword(s):  
High Pressure ◽  
Residence Time ◽  
Flow Rate ◽  
Large Diameter ◽  
Operating Pressure ◽  
Gas Pipelines ◽  
Liquid Holdup ◽  
Wet Gas ◽  
Exploration And Production ◽  
Demand Changes

Esso Australia Ltd. operates two offshore gas platforms for Esso Exploration and Production Australia Inc. and Hematite Petroleum Pty. Ltd. in the Gippsland Basin. Gas and condensate from the Marlin platform flow to the gas plant near Sale, Victoria through a 67 mile, 20 inch pipeline. Gas and condensate from the Barracouta platform flow to the plant through a 30 mile, 18 inch pipeline. Average flowing pressure is 1300 psig. Condensate: gas ratios are 65 bbl/MMscf for Marlin and 15 bbl/MMscf for Barracouta.As these platforms are the only source of supply for the city of Melbourne, gas rates are changed to match gas demand. Changes in gas rate are accompanied by changes in condensate flow. From consideration of liquid holdup and liquid residence time, a method of predicting the condensate flow rate resulting from gas rate change was developed.A controlled run was made to test the prediction. After holding the Marlin gas rate steady at 150 MMscfd for 50 hours to reach equilibrium holdup conditions, the rate was increased to 250 MMscfd and held at this rate for 26 hours to reach equilibrium conditions again. The condensate flow rate out of the pipeline was monitored continually.The Marlin pipeline test demonstrated that changes in condensate flow rate resulting from changes in gas rate in high pressure wet gas pipelines can be predicted within 15 per cent of actual rates using liquid holdup and liquid residence time as input data. In the absence of holdup data from pipeline pigging, Eaton's correlation will provide good values for holdup for wet gas pipelines with operating pressure up to 1500 psig and which traverse relatively flat topography.This work has application in the sizing of liquid surge capacity required to receive condensate from high pressure wet gas pipelines. In many cases, investment in slug catcher facilities can be greatly reduced without risk of overfilling with liquid.

Sign in / Sign up

Export Citation Format

Share Document